The proposed program represents a 5-year continuation of an institutional training grant in the biology of aging, which was encompasses diverse investigators from 7 academic departments at UT Health Science Center San Antonio (UTHSCSA). We request funds to support 10 predoctoral and 6 postdoctoral trainees. The impending avalanche of elderly in the US combined with major recent advances in understanding fundamental mechanisms of aging has created a substantial demand for researchers trained to investigate means of delaying and relieving the ailments of an aging population. UTHSCSA is a premier research institution in the biology of aging, with the largest faculty in the country whose research is devoted primarily to the basic biology of aging. The primary goal of the proposed Training Program is to intellectually prepare both graduate students and postdoctoral fellows for careers as leaders in basic biological research in aging. The Training Program involves 26 faculty members (16 men, 10 women) and takes advantage of the synergies created by intensely collaborative personnel, the unique resources available from our Nathan Shock Center of Excellence in the Biology of Aging and the institutional commitment to, and expanding resources of, the Barshop Institute itself. Trainees will be chosen competitively based on academic excellence, their interest in aging research, and motivation for careers in research. The main activity of each trainee is the development of their faculty- supervised research project, which because of the extensive collaboration among our faculty tends to result surprisingly often in co-mentorships. Trainees have thrived with dual mentorships to the point that we have now institutionalized it as an obligatory feature of our training program Another key component is to require broad knowledge in the biology of aging acquired in our biology of aging course such that trainees' can place their research in an appropriate scientific context. In addition to this formal didactic training, we require trainees to attend the weekly Aging Research Journal Club and present at, as well as attend, our weekly Barshop Institute seminar series and annual trainee retreat. Training in grant writing skills resulting in an F- seris grant proposal for individual NRSAs are accomplished by all trainees within the first 18 months of entering our training program.